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Biomedical subjects

D Bear

Publications and source records attributed to D Bear.

At least 19 recordsLinked to original sources
PubMed2004

Bound on Lorentz and CPT violating boost effects for the neutron.

A search for an annual variation of a daily sidereal modulation of the frequency difference between colocated 129Xe and 3He Zeeman masers sets a stringent limit on boost-dependent Lorentz and CPT violation involving the neutron, consistent with no effect at the level of 150 nHz. In the framework of the general standard-model extension, the present result provides the first clean test for the fermion sector of the symmetry of spacetime under boost transformations at a level of 10(-27) GeV.

Journal Article↗
PubMed1992

Electrodeposition procedure of E. coli RNA polymerase onto gold and deposition of E. coli RNA polymerase onto mica for observation with scanning force microscopy.

Molecules of the transcriptional enzyme E. coli RNA polymerase (RNAP) have been deposited using three different deposition methods: (1) passive adsorption onto gold, (2) electrochemical adsorption onto gold and (3) adsorption onto mica. In all cases SFM imaging was straightforward and reliable, and surface coverage by the protein varied with deposition conditions as expected. To determine the nature of the electrochemical treatment on the gold substrate, cyclic voltammetry was performed with various chemical solutions. Finally, a comparison is made between the SFM images of RNAP obtained with these methods and STM images obtained earlier. Both STM and SFM show strikingly similar results; however, heights and widths of individual molecules differ.

Adsorption↗
PubMed1990

Organic disorders of personality.

Organic illnesses may produce alterations in behavior that closely resemble personality disorders. Careful differential diagnosis is necessary in formulating appropriate treatment.

Adult↗
PubMed1988

Confusional states following posterior cerebral artery infarction.

Four patients with left-sided posterior cerebral artery infarction developed acute confusional states. Fifteen additional patients with confusion following unilateral posterior cerebral artery infarction were identified from a review of the literature; in 14 the lesion was left sided. Destruction or disconnection of dominant hemisphere neocortex from limbic structures, resulting in impairment of focal attention, loss of linguistically organized memory, and/or disruption of temporal sequencing may be responsible for this syndrome.

Acute Disease↗
PubMed1986

Quantitative analysis of cerebral asymmetries. Fronto-occipital correlation, sexual dimorphism and association with handedness.

To investigate the biological and functional significance of cerebral asymmetries, we measured lateral differences of the frontal and occipital poles on computed tomographic scans of 66 adult outpatients with no diagnosed abnormalities. In addition to confirming the greater average sizes of the right frontal and left occipital poles, we found a significant linear correlation relating anterior and posterior difference measures. Men showed greater degrees of frontal and occipital asymmetries than women; reversals of the typical asymmetries were more common among women. Reduction or reversal of the usual left occipital predominance in the presence of typical right frontal predominance was associated with non-right-handedness. These findings clarify and extend prior qualitative observations and relate to the possible role of testosterone in modulation of cortical asymmetries. Reduced structural asymmetries among women and non-right-handers may provide an anatomical basis for clinical and laboratory findings of lessened functional lateralization in these groups.

Adult↗
PubMed1984

Varieties of aggressive behavior in temporal lobe epilepsy.

While an increase in aggression has frequently been reported in association with temporal lobe epilepsy, the validity of this behavioral observation and the relationship of specific aggressive behavior to electrophysiologic abnormality in the human limbic system remain unclear. Case reports of five patients document the clinical importance of aggressive behavior, especially during the interictal period, in patients with temporal lobe epilepsy. Aggressiveness was often encountered together with other deepened emotions and changes in behavior previously described as an interictal behavior syndrome. Variations among the individual patients may clarify the neuroanatomical mechanisms leading to aggression and suggest specific therapeutic interventions.

Adult↗
PubMed1982

Mood, vegetative disturbance, and dexamethasone suppression test after stroke.

Assessments of mood disturbance and "vegetative" (appetite or sleep) disturbance as well as a single-dose dexamethasone suppression test (DST) were carried out in 25 randomly selected stroke patients and in 13 nonstroke control patients hospitalized in a rehabilitation center. Prevalence rates of moderate-to-serve depression of mood and vegetative disturbance were significantly higher in stroke patients than controls (48% and 52% versus 0% and 8%, respectively), as was the prevalence of abnormal DST results (52% versus 8%). Abnormal DST results were associated with the occurrence of moderate to severe mood, appetite, and sleep disturbances among all patients. in 2 stroke patients, repeated DST results paralleled the clinical course. The DST may be useful as an adjunct to the diagnosis and in monitoring the progress of the common and potentially reversible mood and vegetative disturbances occurring after stroke.

Aged↗
PubMed1982

Interictal behaviour in hospitalised temporal lobe epileptics: relationship to idiopathic psychiatric syndromes.

Temporal lobe epileptics undergoing psychiatric hospitalisation were contrasted with patients suffering idiopathic psychiatric syndromes or other epilepsies. Quantitative ratings from blind interviews conducted according to a protocol confirmed the appearance of a statistically distinctive behavioural profile, including the desire for social affiliation, circumstantiality, religious and philosophic interests, and deepened affects, among the temporal lobe epileptics.

Adult↗
PubMed1981

Multiple personality and related dissociative phenomena in patients with temporal lobe epilepsy.

Many patients with temporal lobe epilepsy also experience dissociative episodes. Three patients with multiple personality exhibited alterations in speech pattern, personality, handedness, and sense of personal identity and claimed amnesia for the dissociative episodes. Another 10 patients identified alternative personalities or demons as motivators of ego-alien behavior. Of clinic patients with temporal lobe epilepsy, 33% exhibited some dissociative phenomena, which had no apparent association with individual seizures but always followed the development of the seizure disorder. The authors propose that intensified, dystonic affects, characteristic of the interictal period in temporal lobe epilepsy, may predispose some individuals to dissociative reactions.

Adult↗